Method and apparatus for controlling planarizing characteristics in mechanical and chemical-mechanical planarization of microelectronic substrates

ABSTRACT

A method and apparatus for mechanical and/or chemical-mechanical planarization of microelectronic substrates. In one embodiment, an apparatus for controlling the planarizing characteristics of a microelectronic substrate has a carrier that may be positioned with respect to a polishing medium of a planarizing machine to move with respect to a microelectronic substrate during planarization. The apparatus may also have a modulator with a contact element, and the modulator may be attached to the carrier to position at least a portion of a contact element in front of a leading edge of the substrate by a selected distance during planarization. In operation, the modulator causes the contact element to selectively engage a region of the planarizing surface to modulate the contour of the planarizing surface during planarization.

TECHNICAL FIELD

The present invention relates to mechanical and chemical-mechanicalplanarization of microelectronic substrates. More particularly, thepresent invention relates to controlling the planarizing characteristicsof a microelectronic substrate.

BACKGROUND OF THE INVENTION

Mechanical and chemical-mechanical planarization processes removematerial from the surface of semiconductor wafers, field emissiondisplays and many other microelectronic substrates to form a flatsurface at a desired elevation. FIG. 1 schematically illustrates aplanarizing machine 10 with a platen or base 20, a carrier assembly 30,a polishing pad 40, and a planarizing solution 44 on the polishing pad40. The planarizing machine 10 may also have an under-pad 25 attached toan upper surface 22 of the platen 20 for supporting the polishing pad40. In many planarizing machines, a drive assembly 26 rotates (arrow A)and/or reciprocates (arrow B) the platen 20 to move the polishing pad 40during planarization.

The carrier assembly 30 controls and protects a substrate 12 duringplanarization. The carrier assembly 30 generally has a substrate holder32 with a pad 34 that holds the substrate 12 via suction, and anactuator assembly 36 typically rotates and/or translates the substrateholder 32 (arrows C and D, respectively). However, the substrate holder32 may be a weighted, free-floating disk (not shown) that slides overthe polishing pad 40.

The polishing pad 40 and the planarizing solution 44 may separately, orin combination, define a polishing environment that mechanically and/orchemically removes material from the surface of the substrate 12. Thepolishing pad 40 may be a conventional polishing pad made from arelatively compressible, porous continuous phase matrix material (e.g.,polyurethane), or it may be an abrasive polishing pad with abrasiveparticles fixedly bonded to a suspension medium. In a typicalapplication, the planarizing solution 44 may be a chemical-mechanicalplanarization slurry with abrasive particles and chemicals for use witha conventional non-abrasive polishing pad, or the planarizing solution44 may be a liquid without abrasive particles for use with an abrasivepolishing pad. To planarize the substrate 12 with the planarizingmachine 10, the carrier assembly 30 presses the substrate 12 against aplanarizing surface 42 of the polishing pad 40 in the presence of theplanarizing solution 44. The platen 20 and/or the substrate holder 32then move relative to one another to translate the substrate 12 acrossthe planarizing surface 42. As a result, the abrasive particles and/orthe chemicals in the polishing environment remove material from thesurface of the substrate 12.

Planarizing processes must consistently and accurately produce auniformly planar surface on the substrate to enable precise fabricationof circuits and photo-patterns on the substrate. As the density ofintegrated circuits increases, the uniformity and planarity of thesubstrate surface is becoming increasingly important because it isdifficult to form sub-micron features or photo-patterns to within atolerance of approximately 0.1 μm when the substrate surface is notuniformly planar. Thus, planarizing processes must create a highlyuniform, planar surface on the substrate.

In the competitive semiconductor and microelectronic devicemanufacturing industries, it is also desirable to maximize the yield ofindividual devices or dies on each substrate. Typical semiconductormanufacturing processes fabricate a plurality of dies (e.g., 50-250) oneach substrate. To increase the number of dies that may be fabricated oneach substrate, many manufacturers are increasing the size of thesubstrates to provide more surface area for fabricating additional dies.Thus, to enhance the yield of operable dies on each substrate,planarizing processes should form a planar surface across the substratesurface.

In conventional planarizing processes, however, the substrate surfacemay not be uniformly planar because the rate at which material isremoved from the substrate surface (the “polishing rate”) typicallyvaries from one region on the substrate to another. The polishing rateis a function of several factors, and many of the factors may changethroughout the planarizing process. For example, some of the factorsthat effect the polishing rate across the surface of the substrate areas follows: (1) the distribution of abrasive particles and chemicalsbetween the substrate surface and the polishing pad; (2) the relativevelocity between the polishing pad and the substrate surface; and (3)the pressure distribution across the substrate surface.

One particular problem with conventional planarizing devices and methodsis that the deviation of the surface uniformity in a perimeter region ofthe substrate is generally much greater than that of a central region.In conventional planarizing processes, the polishing rate in a 5-15 mmperimeter region at the substrate edge is generally higher than thepolishing rate in a central region. One reason for the difference in thepolishing rate is that the relative velocity between the substrate andthe polishing pad is generally higher in the perimeter region of thesubstrate than the central region. Another reason for the difference inthe polishing rate is that the edge of the substrate wipes a significantamount of the planarizing solution off of the polishing pad before theplanarizing solution can contact the central region. Conventionalplanarizing devices and methods, therefore, typically produce anon-uniform, center-to-edge planarizing profile across the substratesurface.

To reduce such center-to-edge planarizing profiles, several existingpolishing pads have holes or grooves that transport a portion of theplanarizing solution below the substrate surface during planarization. ARodel IC-1000 polishing pad, for example, is a relatively soft, porouspolyurethane pad with a number of large slurry wells approximately0.05-0.10 inches in diameter that are spaced apart from one anotheracross the planarizing surface by approximately 0.125-0.25 inches.During planarization, small volumes of slurry are expected to fill thelarge wells, and then hydrodynamic forces created by the motion of thesubstrate are expected to draw the slurry out of the wells in a mannerthat wets the substrate surface. However, even IC-1000 pads may producesignificant center-to-edge planarizing profiles indicating that theperimeter of the substrate presses some of the slurry out of the wellsahead of the center of the substrate. U.S. Pat. No. 5,216,843 describesanother polishing pad with a plurality of macro-grooves formed inconcentric circles and a plurality of micro-grooves radially crossingthe macro-grooves. Although grooved pads may improve the planarity ofthe substrate surface, substrates planarized with such pads stillexhibit non-uniformities across the substrate surface indicating anon-uniform distribution of planarizing solution and abrasive particlesunder the substrate.

Other techniques for reducing the center-to-edge planarizing profilereduce the differences in the relative velocity between the perimeterand central regions. For example, one existing planarizing machine holdsthe polishing pad stationary and orbits the substrate in an eccentricpattern across the polishing pad. In another related planarizationprocess, the substrate is held in a precession wafer holder that allowsthe substrate to precess with respect to the wafer holder duringplanarization. Although reducing the difference in the relative velocityacross the substrate surface reduces the center-to-edge planarizingprofile, existing planarizing machines may still produce significantdeviations in the surface uniformity between the perimeter region andthe central region.

In light of the results of conventional planarizing devices, thedeviation of the surface uniformity in the perimeter region may be sogreat that it impairs or ruins dies formed in the perimeter region.Thus, because a defective 5-15 mm perimeter region affects a largersurface area and more dies on a 12-inch substrate than an 8-inchsubstrate, the center-to-edge planarizing profile significantly impactsthe yield of larger substrates.

SUMMARY OF THE INVENTION

The present invention is a method and apparatus for mechanical and/orchemical-mechanical planarization of microelectronic substrates. In oneembodiment in accordance with the principles of the present invention,an apparatus for controlling the planarizing characteristics of amicroelectronic substrate has a carrier that may be positioned withrespect to a polishing medium of a planarizing machine. The carrier maybe a substrate holder of the planarizing machine or another carrierindependent from the substrate holder that moves with respect to amicroelectronic substrate during planarization of the substrate. Theapparatus may also have a modulator attached to the carrier, and themodulator may have a contact element for engaging the polishing medium.The modulator, for example, may be attached to the carrier to positionat least a portion of the contact element in front of a leading edge ofthe substrate by a selected distance during planarization. In operation,the contact element selectively engages a portion of the planarizingsurface proximate to the leading edge of the substrate to modulate thecontour of the planarizing surface of the polishing medium.

In one particular embodiment in which the carrier is a substrate holder,the modulator is attached to the substrate holder to position thecontact element superadjacent to an exposed portion of a standing wavethat forms at the leading edge of the substrate during planarization.The contact element operates by engaging the exposed portion of thestanding wave in a manner that modulates the contour of a residualportion of the standing wave under a perimeter region of the substrate.For example, the modulator may be a passive modulator in which thecontact element has a bottom surface with a desired contour to attenuateor shift the residual portion of the standing wave. In anotherembodiment, the modulator may be an active modulator having an actuatorthat carries the contact element and a controller coupled to theactuator. The controller may be programmed to drive the actuator in amanner that selectively moves a bottom surface of the contact elementagainst the exposed portion of the standing wave. The particular motionof the actuator may be selected to continually shift a pressure point ofthe residual portion of the standing wave and/or attenuate the residualportion of the standing wave. For example, the active modulator may movethe contact element against the exposed portion of the standing wave ina manner that oscillates a pressure point of the residual portion of thestanding wave under the perimeter region of the substrate to average theeffect of the pressure point over a larger surface area on thesubstrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a planarizing machine in accordance withthe prior art.

FIG. 2 is a schematic view of a planarizing machine with a device forcontrolling the planarizing characteristics of a microelectronicsubstrate in accordance with an embodiment of the invention.

FIG. 3 is a partial schematic cross-sectional view of a planarizingmachine with a device for controlling the planarizing characteristics ofa microelectronic substrate in accordance with one embodiment of theinvention.

FIG. 4A is a partial schematic cross-sectional view illustrating the oneaspect of the operation of the device of FIG. 3.

FIG. 4B is a partial schematic cross-sectional view illustrating anotheraspect of the operation of the device of FIG. 3.

FIG. 5A is a partial schematic cross-sectional view of a planarizingmachine with another device for controlling the planarizingcharacteristics of a microelectronic substrate in accordance withanother embodiment of the invention.

FIG. 5B is a partial schematic cross-sectional view illustrating theoperation of the device of FIG. 5A.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is an apparatus and method for mechanical and/orchemical-mechanical planarization of substrates used in themanufacturing of microelectronic devices. Many specific details ofcertain embodiments of the invention are set forth in the followingdescription and in FIGS. 2-5B to provide a thorough understanding ofsuch embodiments. One skilled in the art, however, will understand thatthe present invention may have additional embodiments and may bepracticed without several of the details described in the followingdescription.

FIG. 2 is a schematic view of a planarizing machine 100 in accordancewith one embodiment of the invention. The planarizing machine 100includes a carrier assembly 130 and an active modulator 170 forcontrolling the planarizing characteristics of a microelectronicsubstrate 12. The features and advantages of the modulator 170 are bestunderstood in the context of the structure and operation of theplanarizing machine 100. Thus, the general features of the planarizingmachine 100 will be described initially.

The planarizing machine 100 may have a platen or a support table 110carrying an underpart 112 at a work station or a planarization stationwhere a section “A” of a planarizing medium 100 is positioned. Theunderpart 112 may be a substantially incompressible support memberattached to the table 110 to provide a flat, solid surface to which aparticular section of the polishing medium 140 may be secured duringplanarization. In other applications, however, the underpart 112 may bea compressible pad to provide a more conformal polishing medium. Theplanarizing machine 110 100 also has a plurality of rollers to guide,position, and hold the polishing medium 140 over the underpart 112. Inone embodiment, the rollers include a supply roller 120, first andsecond idler rollers 121a and 121b, first and second guide rollers 122aand 122b, and a take-up roller 123. The supply roller 120 carries anunused portion of the polishing medium 140, and the take-up roller 123carries the used portion of the polishing medium 140. The supply roller120 and the take-up roller 123 are driven rollers to sequentiallyadvance the unused portion of the polishing medium 140 onto theunderpart 112. As such, an unused section of the planarizing medium maybe quickly substituted for a worn, used section to provide a consistentsurface for planarizing the substrate. The first idler roller 121a andthe first guide roller 122a position the polishing medium 140 slightlybelow the underpart 112 so that the supply and take-up rollers 120 and123 stretch the polishing medium 140 over the underpart 112 to hold itstationary during planarization.

The planarizing machine 100 also has a carrier assembly 130 to translatethe substrate 12 across a planarizing surface 150 of the polishingmedium 140. In one embodiment, the carrier assembly 130 has a substrateholder 132 to pick up, hold and release the substrate 12 at appropriatestages of the planarization process. The carrier assembly 130 may alsohave a support gantry 134 carrying an actuator 136 so that the actuator136 can translate along the gantry 134. The actuator 136 preferably hasa drive shaft 137 coupled to an arm assembly 138 that carries thesubstrate holder 132. In operation, the gantry 134 raises and lowers thesubstrate 12, and the actuator 136 orbits the substrate 12 about an axisB-B via the drive shaft 137. In another embodiment, the arm assembly 138may also have an actuator (not shown) to drive a shaft 139 of the armassembly 138 and thus rotate the substrate holder 132 about an axis C—Cin addition to orbiting the substrate holder 132 about the axis B—B.

The modulator 170 may be an active modulator 170 with a contact element172, an actuator 174 carrying the contact element 172, and a controller180 coupled to the actuator 174. In one embodiment, the actuator 174 isattached to the substrate holder 132 to position at least a portion ofthe contact element 172 in front of leading edge of the substrate 12during planarization. For example, the actuator 174 and the contactelement 172 may surround the substrate 12 so that a portion of thecontact element 172 is positioned superadjacent to an area on thepolishing medium 140 in front of a leading edge of the substrate 12irrespective of the direction that the substrate holder 132 is moving.The contact element 172 may accordingly be a carrier ring that containsthe substrate 12 within the substrate holder 132. As discussed infurther detail below, the contact element 172 selectively engages theplanarizing surface 150 to modulate the contour of the planarizingsurface 150 under a perimeter region of the substrate 12.

FIG. 3 is a partial schematic cross-sectional view of the substrateholder 132 showing a portion of the active modulator 170 in greaterdetail. The actuator 174 may be a single linear displacement device or aplurality of displacement devices embedded in the substrate holder 132in a ring around the substrate 12. The contact element 172 may thus be aring configured to position a bottom surface 173 of the contact element172 superadjacent to a portion of the planarizing surface 150. In oneparticular embodiment, the actuator 174 is a piezoelectric ring drivenby electric signals from the controller 180. The contact element 172 mayaccordingly be a metal, ceramic or other type of ring attached to thepiezoelectric actuator 174.

One aspect of the invention is the discovery that a leading edge 14 ofthe substrate 12 having a motion “M” forms a standing wave 152 in theplanarizing surface 150 of the polishing medium 140. The particularwaveform of the standing wave 152 is a function of several factors, suchas the pad type, substrate structure, planarizing solution, downforce,relative velocity and other factors. The standing wave 152 shown in FIG.3 is a schematic representation of a standing wave that does notnecessarily represent the waveform of an actual standing wave. As such,the amplitude and wave length of the standing wave 152 shown in FIG. 3are exaggerated for illustrative purposes. Additionally, a planarizingsolution is not shown on top of the planarizing surface 150 for purposesof clarity, but it will be appreciated that a planarizing solution istypically dispensed onto the planarizing surface 150 duringplanarization.

In operation, the controller 180 drives the actuator 174 to move thecontact element 172 vertically and/or horizontally with respect to anexposed portion 154 of the standing wave 152. For example, in onepossible application of the active modulator 170, the actuator 174 mayhold a bottom surface 173 of the contact element 172 in engagement withthe planarizing surface 150 (not shown in FIG. 3) at a set position withrespect to the exposed portion 154 of the standing wave 152 to alter aresidual portion of the standing wave 156 with respect to the substrate12. In another possible application of the active modulator 170, theactuator 174 may continuously move the contact element 172 in engagementwith the planarizing surface 150 to continuously alter the contour ofthe planarizing surface 150 in a manner that produces a plurality ofdifferent waveforms on the planarizing surface 150 instead of thestanding wave 152. In still another possible application of the activemodulator 170, the actuator may move the contact element 172 intoengagement with the planarizing surface 150 at a selected frequency,amplitude and phase with respect to the standing wave 152 to cancel thestanding wave 152 on the planarizing surface 150. Thus, the controller180 may be programmed to selectively operate the active modulator 170 ina desired manner according to the particular application.

FIG. 4A is a schematic partial cross-sectional view illustrating theaforementioned possible application in which the contact element 170172is held at a set position against the planarizing surface 150. InFIG. 4A, the controller 180 drives the actuator 174 to position thebottom surface 173 of the contact element 172 a distance h1 away from areference height ho where the bottom surface 173 engages the exposedportion 154 of the standing wave 152. The actuator 174 may hold thebottom surface 173 in this position such that the force exerted by thecontact element 172 against the exposed portion 154 changes the residualportion 156 of the standing wave 152 with respect to the perimeterregion 15 of the substrate 12. Thus, in this possible application, thecontact element 172 may be positioned to affect the boundary conditionof the standing wave 152 in a manner that attenuates and/or changes theposition of pressure points of the residual portion 156 with respect tothe substrate 12.

FIG. 4B is another schematic cross-sectional view that, together withFIG. 4A, illustrates the aforementioned possible application in whichthe actuator 174 continuously moves the contact element 172 inengagement with the planarizing surface 150 to produce a plurality ofdifferent waveforms on the planarizing surface 150. In this application,the actuator 174 may move the bottom surface 173 of the contact element172 between the position h₁ (FIG. 4A) and a position h₂ (FIG. 4B) at oneor more frequencies to continuously alter the waveform on theplanarizing surface. As such, the standing wave 152 on the planarizingsurface 150 will be replaced by a number of different waves in which thepressure points act on different radial positions of the substrate 12.For example, if the actuator 174 moves the contact element 172 from theposition h₁ to the position h₂ during planarization, a number ofpressure points 158 and 159 may move with respect to the substrate. Theactuator 174, accordingly, may move the contact element 172 duringplanarization to change the radial locations of the pressure points withrespect to the substrate 12 so that the effects of the pressure pointsmay be spread across a larger surface area of the substrate 12. In thisapplication, therefore, the active modulator 170 is expected to reducethe concentration of a high pressure forces at relatively fixed radialpositions on the substrate 12.

To program the controller 180 to drive the actuator 174, an operator maymeasure the planarity of the perimeter region 15 of a number ofsubstrates that were planarized while holding the contact element 172 ata number of different set positions or moving the contact element 172 ata number of selected frequencies and amplitudes. Since the shape of thestanding wave 150 152 is a function of such factors as the pad type,substrate configuration, relative velocity, slurry distribution and downforce, the particular position or movement of the contact element 172may be determined empirically for each specific planarization process.Based upon the actual deviation in the surface uniformity of theperimeter region 15, and also based upon the size of the perimeterregion 15, a person skilled in the art can determine the best positionor motion of the contact element 172 to program into the controller 180.

The planarizing machine 100 with the active modulator 170 is expected toreduce the deviation in the surface uniformity in the perimeter regionof a microelectronic substrate. Unlike conventional devices and methodsfor reducing the edge effect in planarization, several embodiments ofthe present invention are expected to enhance the uniformity of thesubstrate surface by altering the pressure exerted against the perimeterregion of the substrate. The contact element 172, more particularly, mayshift and/or attenuate the residual portion of the standing wave underthe perimeter region 15 of the substrate 12 to reduce the concentrationof high pressure points at substantially fixed radial positions on thesubstrate 12. As a result, the modulator 170 is expected to limit largedeviations in the surface uniformity to a region approximately 2-5 mmfrom the substrate edge as opposed to the 5-15 mm perimeter regionproduced by conventional devices. Moreover, compared to conventionalsystems, the modulator 170 is also expected to reduce the extent of thedeviations in surface uniformity in the 2-5 mm perimeter region. Thus,the planarizing machine 100 with the active modulator 170 is expected toincrease the yield of operable dies on each substrate.

FIGS. 5A and 5B are partial schematic cross-sectional views of anotherembodiment of a modulator 270 for controlling the planarizingcharacteristics of microelectronic substrates. Referring to FIG. SA, themodulator 270 may be a passive modulator in which the contact element272 is fixedly attached to or integrally formed with the substrateholder 132. The contact element 272 may have a bottom surface 273 with adesired contour to modulate a residual portion 156 of the standing wave152 on the planarizing surface 150 under the perimeter region 15 of thesubstrate 12. As described above with respect to determining thewaveform for moving the active contact element 172, the contour of thebottom surface 273 may be determined empirically to shift or attenuatethe residual portion 156 of the standing wave. Thus, the shape of thebottom surface 273 shown in FIGS. 5A and 5B is for illustrativepurposes, and it will be appreciated that other shapes may be used toadapt the contact element 272 to the specific planarizing process. Thewidth of the contact element 172 and its distance from the leading edge14 of the substrate 12 can also be determined empirically at differentoperating conditions such as wafer velocity.

FIG. 5B illustrates the operation of the passive modulator 270 in whichthe substrate holder 132 presses the bottom surface 273 against theexposed portion 154 of the standing wave 152 on the planarizing surface150. As described above, the shape of the bottom surface 273 may beconfigured either to attenuate and/or shift the residual portion 156 ofthe standing wave 152. Unlike the active modulator 170, however, thepassive modulator 270 does not oscillate the pressure points of theresidual portion 156 because the contact face 273 remains at the sameelevation relative to the polishing pad 140 during planarization.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described above for purposes of illustration,but that various modifications may be made without deviating from thespirit and scope of the invention. For example, the contact element 172may be an integral part of the piezoelectric actuator 174. Additionally,the shape of the bottom surface 173 of the contact element 172 may alsobe contoured as shown by the bottom surface 273 of the contact element272. Accordingly, the invention is not limited except as by the appendedclaims.

1. An apparatus for controlling planarizing characteristics of a microelectronic substrate, comprising: a carrier positionable with respect to a polishing medium to move with a microelectronic substrate during planarization on a planarizing surface of the polishing medium, the carrier comprising a microelectronic substrate holder having a chuck and a rim; and a modulator having a contact element, the modulator being attached to the substrate holder to position the contact element radially outwardly from a perimeter edge of the substrate so that at least a portion of the contact element is in front of the leading edge of the substrate during planarization and superadjacent to an exposed portion of a standing wave on the planarizing surface, the modulator being configured to cause the contact element to selectively engage the exposed portion of the standing wave to modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator comprises a passive modulator and the contact element has a desired contour to attenuate an amplitude of the residual portion of the standing wave under the perimeter region of the substrate.
 2. An apparatus for controlling planarizing characteristics of a microelectronic substrate, comprising: a carrier positionable with respect to a polishing medium to move with a microelectronic substrate during planarization on a planarizing surface of the polishing medium, the carrier comprising a microelectronic substrate holder having a chuck and a rim; and a modulator having a contact element, the modulator being attached to the substrate holder to position the contact element radially outwardly from a perimeter edge of the substrate so that at least a portion of the contact element is in front of the leading edge of the substrate during planarization and superadjacent to an exposed portion of a standing wave on the planarizing surface, the modulator being configured to cause the contact element to selectively engage the exposed portion of the standing wave to modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator further comprises an active modulator having a controller and an actuator carrying the contact element, the controller driving the actuator to selectively move the contact element in engagement with the exposed portion of the standing wave in a manner that shifts a pressure point of the residual portion of the standing wave with respect to the substrate.
 3. An apparatus for controlling planarizing characteristics of a microelectronic substrate, comprising: a carrier positionable with respect to a polishing medium to move with a microelectronic substrate during planarization on a planarizing surface of the polishing medium, the carrier comprising a microelectronic substrate holder having a chuck and a rim; and a modulator having a contact element, the modulator being attached to the substrate holder to position the contact element radially outwardly from a perimeter edge of the substrate so that at least a portion of the contact element is in front of the leading edge of the substrate during planarization and superadjacent to an exposed portion of a standing wave on the planarizing surface, the modulator being configured to cause the contact element to selectively engage the exposed portion of the standing wave to modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator further comprises an active piezoelectric modulator having a controller and an actuator carrying the contact element, the controller driving the actuator to selectively move the contact element in engagement with the exposed portion of the standing wave in a manner that continually shifts a pressure point of the residual portion of the standing wave with respect to the substrate.
 4. The apparatus of claim 3 wherein the actuator comprises a piezoelectric actuator.
 5. An apparatus for controlling planarizing characteristics of a microelectronic substrate, comprising: a carrier positionable with respect to a polishing medium to move with a microelectronic substrate during planarization on a planarizing surface of the polishing medium, the carrier comprising a microelectronic substrate holder having a chuck and a rim; and a modulator having a contact element, the modulator being attached to the substrate holder to position the contact element radially outwardly from a perimeter edge of the substrate so that at least a portion of the contact element is in front of the leading edge of the substrate during planarization and superadjacent to an exposed portion of a standing wave on the planarizing surface, the modulator being configured to cause the contact element to selectively engage the exposed portion of the standing wave to modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator further comprises an active modulator having a controller and an a piezoelectric actuator carrying the contact element, the controller driving the actuator to selectively move the contact element in engagement with the exposed portion of the standing wave in a manner that attenuates the residual portion of the standing wave under the substrate.
 6. The apparatus of claim 5 wherein the actuator comprises a piezoelectric actuator.
 7. An apparatus for controlling planarizing characteristics of a microelectronic substrate, comprising: a carrier positionable with respect to a polishing medium to move with a microelectronic substrate during planarization on a planarizing surface of the polishing medium, the carrier comprising a microelectronic substrate holder having a chuck and a rim; and a modulator having a contact element, the modulator being attached to the substrate holder to position the contact element radially outwardly from a perimeter edge of the substrate so that at least a portion of the contact element is in front of the leading edge of the substrate during planarization and superadjacent to an exposed portion of a standing wave on the planarizing surface, the modulator being configured to cause the contact element to selectively engage the exposed portion of the standing wave to modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator further comprises an active modulator having a controller and an a piezoelectric actuator carrying the contact element, the controller driving the actuator to selectively move the contact element in engagement with the exposed portion of the standing wave in a manner that attenuates the residual portion of the standing wave and continually shifts a pressure point of the residual portion of the standing wave with respect to the substrate.
 8. The apparatus of claim 7 wherein the actuator comprises a piezoelectric actuator.
 9. An apparatus for controlling planarizing characteristics of a microelectronic substrate, comprising: a carrier positionable with respect to a polishing medium having a planarizing surface to move with a microelectronic substrate during planarization on the planarizing surface, the carrier further including a microelectronic substrate holder having a chuck and a rim around the chuck; and a pad surface regulator having a waveform surface, the regulator being attached to the carrier substrate holder to position at least a portion of the waveform surface in front of a leading edge of the substrate by a selected distance the waveform surface radially outwardly from a perimeter edge of the substrate and being superadjacent to an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization, and the regulator being configured to cause the waveform surface to selectively engage the polishing medium the regulator engaging the waveform surface with the exposed portion of the standing wave to modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate to alter a contour of a planarizing surface of the polishing medium under a perimeter region of the substrate, the regulator further comprising an active modulator having a controller and a piezoelectric actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform surface that attenuates the residual portion of the standing wave under the perimeter portion of the substrate.
 10. The apparatus of claim 9 wherein the carrier comprises a microelectronic substrate holder having a chuck and a rim around the chuck, the regulator being attached to the substrate holder and the waveform surface being positioned radially outwardly from a perimeter edge of the substrate.
 11. The apparatus of claim 10 wherein the regulator is attached to the substrate holder to position the waveform surface superadjacent to an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization, and wherein the regulator engages the waveform surface with the exposed portion of the standing wave to modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate.
 12. The apparatus of claim 11 9 wherein the regulator comprises a passive regulator and the waveform surface has a desired contour defining a static waveform to attenuate an amplitude of the residual portion of the standing wave under the perimeter region of the substrate.
 13. The apparatus of claim 11 9 wherein the regulator comprises a passive regulator and the waveform surface has a desired contour defining a static waveform to shift a pressure point of the residual portion of the standing wave with respect to the perimeter edge of the substrate.
 14. The apparatus of claim 11 9 wherein the regulator comprises an active modulator having a controller and an actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform that shifts a pressure point of the residual portion of the standing wave with respect to the perimeter edge of the substrate.
 15. The apparatus of claim 11 9 wherein the regulator comprises an active modulator having a controller and an actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform that continually shifts a pressure point of the residual portion of the standing wave with respect to the perimeter edge of the substrate.
 16. The apparatus of claim 15 wherein the actuator comprises a piezoelectric actuator.
 17. The apparatus of claim 11 wherein the regulator comprises an active modulator having a controller and an actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform surface that attenuates the residual portion of the standing wave under the perimeter portion of the substrate.
 18. The apparatus of claim 17 wherein the actuator comprises a piezoelectric actuator.
 19. The apparatus of claim 11 9 wherein the regulator comprises an active modulator having a controller and an actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform that attenuates the residual portion of the standing wave under the perimeter portion of the substrate and continually shifts a pressure point of the residual portion of the standing wave with respect to the perimeter edge of the substrate.
 20. The apparatus of claim 19 wherein the actuator comprises a piezoelectric actuator.
 21. An apparatus for controlling planarizing characteristics of a microelectronic substrate, comprising: a carrier assembly having a support member positionable over a polishing medium and a substrate holder attached to the support member, the substrate holder having a chuck to hold a microelectronic substrate during planarization, and a modulator attached to the substrate holder, the modulator having a contact element spaced apart from a perimeter edge of the substrate and the modulator being configured to cause the contact element to selectively engage a region of the polishing medium, wherein the modulator is attached to the substrate holder to position the contact element superadjacent to an exposed portion of a standing wave on a planarizing surface of the polishing medium formed at the leading edge of the substrate during planarization and the contact element engages the exposed portion of the standing wave to selectively modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator further comprises an active modulator having a controller and an actuator carrying the contact element, the controller driving the actuator to selectively move the contact element in engagement with the exposed portion of the standing wave in a manner that shifts a pressure point of the residual portion of the standing wave with respect to the substrate.
 22. An apparatus for controlling planarizing characteristics of a microelectronic substrate, comprising: a carrier assembly having a support member positionable over a polishing medium and a substrate holder attached to the support member, the substrate holder having a chuck to hold a microelectronic substrate during planarization; and a modulator attached to the substrate holder, the modulator having a contact element spaced apart from a perimeter edge of the substrate and the modulator being configured to cause the contact element to selectively engage a region of the polishing medium, wherein the modulator is attached to the substrate holder to position the contact element superadjacent to an exposed portion of a standing wave on a planarizing surface of the polishing medium formed at the leading edge of the substrate during planarization and the contact element engages the exposed portion of the standing wave to selectively modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator further comprises an active modulator having a controller and an a piezoelectric actuator carrying the contact element, the controller driving the actuator to selectively move the contact element in engagement with the exposed portion of the standing wave in a manner that continually shifts a pressure point of the residual portion of the standing wave with respect to the substrate.
 23. The apparatus of claim 22 wherein the actuator comprises a piezoelectric actuator.
 24. An apparatus for controlling planarizing characteristics of a microelectronic substrate, comprising: a carrier assembly having a support member positionable over a polishing medium and a substrate holder attached to the support member, the substrate holder having a chuck to hold a microelectronic substrate during planarization; and a modulator attached to the substrate holder, the modulator having a contact element spaced apart from a perimeter edge of the substrate and the modulator being configured to cause the contact element to selectively engage a region of the polishing medium, wherein the modulator is attached to the substrate holder to position the contact element superadjacent to an exposed portion of a standing wave on a planarizing surface of the polishing medium formed at the leading edge of the substrate during planarization and the contact element engages the exposed portion of the standing wave to selectively modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator further comprises an active modulator having a controller and an a piezoelectric actuator carrying the contact element, the controller driving the actuator to selectively move the contact element in engagement with the exposed portion of the standing wave in a manner that attenuates the residual portion of the standing wave under the substrate.
 25. The apparatus of claim 24 wherein the actuator comprises a piezoelectric actuator.
 26. An apparatus for controlling planarizing characteristics of a microelectronic substrate, comprising: a carrier assembly having a support member positionable over a polishing medium and a substrate holder attached to the support member, the substrate holder having a chuck to hold a microelectronic substrate during planarization; and a modulator attached to the substrate holder, the modulator having a contact element spaced apart from a perimeter edge of the substrate and the modulator being configured to cause the contact element to selectively engage a region of the polishing medium, wherein the modulator is attached to the substrate holder to position the contact element superadjacent to an exposed portion of a standing wave on a planarizing surface of the polishing medium formed at the leading edge of the substrate during planarization and the contact element engages the exposed portion of the standing wave to selectively modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator further comprises an active modulator having a controller and an a piezoelectric actuator carrying the contact element, the controller driving the actuator to selectively move the contact element in engagement with the exposed portion of the standing wave in a manner that attenuates the residual portion of the standing wave and continually shifts a pressure point of the residual portion of the standing wave with respect to the substrate.
 27. The apparatus of claim 26 wherein the actuator comprises a piezoelectric actuator.
 28. An apparatus for controlling planarizing characteristics of a microelectronic substrate, comprising: a carrier assembly having a support member positionable over a polishing medium and a substrate holder attached to the support member, the substrate holder having a chuck to hold a microelectronic substrate during planarization; and a pad surface modulator attached to the substrate holder, the modulator having a waveform surface spaced apart from a perimeter edge of the substrate, the modulator being configured to cause the waveform surface to selectively engage the polishing medium to alter a contour of a planarizing surface of the polishing medium under a perimeter region of the substrate.
 29. The apparatus of claim 28 wherein the modulator is attached to the substrate holder to position the waveform surface superadjacent to an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization, and wherein the modulator engages the waveform surface with the exposed portion of the standing wave to alter the contour of a residual portion of the standing wave on the planarizing surface under the perimeter region of the substrate.
 30. The apparatus of claim 29 wherein the modulator comprises a passive modulator and the waveform surface has a desired contour defining a static waveform to attenuate the amplitude of the residual portion of the standing wave under the perimeter region of the substrate.
 31. The apparatus of claim 29 wherein the modulator comprises a passive modulator and the waveform surface has a desired contour to shift a pressure point of the residual portion of the standing wave with respect to the perimeter edge of the substrate.
 32. The apparatus of claim 29 wherein the modulator further comprises an active modulator having a controller and an actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform that continually shifts a pressure point of the residual portion of the standing wave with respect to the perimeter edge of the substrate.
 33. The apparatus of claim 29 wherein the modulator further comprises an active modulator having a controller and an actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform that continually shifts a pressure point of the residual portion of the standing wave with respect to the perimeter edge of the substrate.
 34. The apparatus of claim 29 wherein the modulator further comprises an active modulator having a controller and an actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform that attenuates the residual portion of the standing wave under the perimeter portion of the substrate.
 35. The apparatus of claim 29 wherein the modulator further comprises an active modulator having a controller and an actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform that attenuates the residual portion of the standing wave under the perimeter portion of the substrate and continually shifts a pressure point of the residual portion of the standing wave with respect to the perimeter edge of the substrate.
 36. A planarizing machine, comprising: a table with a support base; a polishing medium mounted on the support base; a carrier assembly having a substrate holder positionable over the polishing medium, the substrate holder having a chuck to hold a microelectronic substrate, wherein at least one of the polishing medium and the substrate holder moves to translate a microelectronic substrate across a planarizing surface of the polishing medium during planarization; and a modulator attached to the substrate holder, the modulator having a contact element spaced apart from a perimeter edge of the substrate and the modulator being configured to cause the contact element to selectively engage a region of the planarizing surface proximate to the leading edge of the substrate as the substrate is planarized, wherein the modulator is attached to the substrate holder to position the contact element superadjacent to an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization and the modulator engages the contact element with the exposed portion of the standing wave to selectively modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator further comprises an active modulator having a controller and an actuator carrying the contact element, the controller driving the actuator to selectively move the contact element in engagement with the exposed portion of the standing wave in a manner that shifts a pressure point of the residual portion of the standing wave with respect to the substrate.
 37. A planarizing machine, comprising: a table with a support base; a polishing medium mounted on the support base; a carrier assembly having a substrate holder positionable over the polishing medium, the substrate holder having a chuck to hold a microelectronic substrate, wherein at least one of the polishing medium and the substrate holder moves to translate a microelectronic substrate across a planarizing surface of the polishing medium during planarization; and a modulator attached to the substrate holder, the modulator having a contact element spaced apart from a perimeter edge of the substrate and the modulator being configured to cause the contact element to selectively engage a region of the planarizing surface proximate to the leading edge of the substrate as the substrate is planarized, wherein the modulator is attached to the substrate holder to position the contact element superadjacent to an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization and the modulator engages the contact element with the exposed portion of the standing wave to selectively modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator further comprises an active modulator having a controller and an a piezoelectric actuator carrying the contact element, the controller driving the actuator to selectively move the contact element in engagement with a dynamic waveform surface that contacts the exposed portion of the standing wave in a manner that continually shifts a pressure point of the residual portion of the standing wave with respect to the substrate.
 38. The apparatus of claim 37 wherein the actuator comprises a piezoelectric actuator.
 39. A planarizing machine, comprising: a table with a support base; a polishing medium mounted on the support base; a carrier assembly having a substrate holder positionable over the polishing medium, the substrate holder having a chuck to hold a microelectronic substrate, wherein at least one of the polishing medium and the substrate holder moves to translate a microelectronic substrate across a planarizing surface of the polishing medium during planarization; and a modulator attached to the substrate holder, the modulator having a contact element spaced apart from a perimeter edge of the substrate and the modulator being configured to cause the contact element to selectively engage a region of the planarizing surface proximate to the leading edge of the substrate as the substrate is planarized, wherein the modulator is attached to the substrate holder to position the contact element superadjacent to an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization and the modulator engages the contact element with the exposed portion of the standing wave to selectively modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator further comprises an active modulator having a controller and an a piezoelectric actuator carrying the contact element, the controller driving the actuator to selectively move the contact element in engagement with the exposed portion of the standing wave in a manner that attenuates the residual portion of the standing wave under the substrate.
 40. The apparatus of claim 39 wherein the actuator comprises a piezoelectric actuator.
 41. A planarizing machine, comprising: a table with a support base; a polishing medium mounted on the support base; a carrier assembly having a substrate holder positionable over the polishing medium, the substrate holder having a chuck to hold a microelectronic substrate, wherein at least one of the polishing medium and the substrate holder moves to translate a microelectronic substrate across a planarizing surface of the polishing medium during planarization; and a modulator attached to the substrate holder, the modulator having a contact element spaced apart from a perimeter edge of the substrate and the modulator being configured to cause the contact element to selectively engage a region of the planarizing surface proximate to the leading edge of the substrate as the substrate is planarized, wherein the modulator is attached to the substrate holder to position the contact element superadjacent to an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization and the modulator engages the contact element with the exposed portion of the standing wave to selectively modulate a contour of a residual portion of the standing wave on the planarizing surface under a perimeter region of the substrate, and wherein the modulator further comprises an active modulator having a controller and an a piezoelectric actuator carrying the contact element, the controller driving the actuator to selectively move the contact element in engagement with the exposed portion of the standing wave in a manner that attenuates the residual portion of the standing wave and continually shifts a pressure point of the residual portion of the standing wave with respect to the substrate.
 42. The apparatus of claim 41 wherein the actuator comprises a piezoelectric actuator.
 43. A planarizing machine, comprising: a table with a support base; a polishing medium mounted on the support base; a carrier assembly having a substrate holder positionable over the polishing medium, the substrate holder having a chuck to hold a microelectronic substrate, wherein at least one of the polishing medium and the substrate holder moves to translate the microelectronic substrate across a planarizing surface of the polishing medium during planarization; and a pad surface modulator attached to the substrate holder, the modulator having a waveform surface spaced apart from a perimeter edge of the substrate, and the modulator being configured to cause the waveform surface to selectively engage the planarizing surface to alter a contour of the planarizing surface under a perimeter region of the substrate during planarization.
 44. The apparatus of claim 43 wherein the modulator is attached to the substrate holder to position the waveform surface superadjacent to an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization, and wherein the modulator engages the waveform surface with the exposed portion of the standing wave to alter the contour of a residual portion of the standing wave on the planarizing surface under the perimeter region of the substrate.
 45. The apparatus of claim 44 wherein the modulator comprises a passive modulator and the waveform surface has a desired contour defining a static waveform to attenuate the amplitude of the residual portion of the standing wave under the perimeter region of the substrate.
 46. The apparatus of claim 44 wherein the modulator comprises a passive modulator and the waveform surface has a desired contour to shift a pressure point of the residual portion of the standing wave with respect to the perimeter edge of the substrate.
 47. The apparatus of claim 44 wherein the modulator further comprises an active modulator having a controller and an actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform that shifts a pressure point of the residual portion of the standing wave with respect to the substrate.
 48. The apparatus of claim 44 wherein the modulator further comprises an active modulator having a controller and an actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform that continually shifts a pressure point of the residual portion of the standing wave with respect to the perimeter edge of the substrate.
 49. The apparatus of claim 44 wherein the modulator further comprises an active modulator having a controller and an actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform that attenuates the residual portion of the standing wave under the perimeter portion of the substrate.
 50. The apparatus of claim 44 wherein the modulator further comprises an active modulator having a controller and an actuator carrying the waveform surface, the actuator selectively moving the waveform surface in contact with the exposed portion of the standing wave to define a dynamic waveform that attenuates the residual portion of the standing wave under the perimeter portion of the substrate and continually shifts a pressure point of the residual portion of the standing wave with respect to the perimeter edge of the substrate.
 51. In microelectronic device manufacturing, a method for controlling edge uniformity in planarization processes using a polishing medium, comprising modulating the contour of a planarizing surface on the polishing medium in a region spaced outwardly from a leading edge of a microelectronic substrate while the substrate is being planarized on the polishing medium by engaging a contact element of a modulator with an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization to modulate the contour of a residual portion of the standing wave under a perimeter region of the substrate, and wherein the modulator comprises an active modulator having an actuator carrying the contact element and a controller coupled to the actuator, and wherein engaging the contact element with the exposed portion of the standing wave comprises selectively driving the actuator to move the contact element against the exposed portion of the standing wave in a manner that shifts a pressure point of the residual portion of the standing wave under a perimeter region of the substrate.
 52. In microelectronic device manufacturing, a method for controlling edge uniformity in planarization processes using a polishing medium comprising modulating the contour of a planarizing surface on the polishing medium in a region spaced outwardly from a leading edge of a microelectronic substrate while the substrate is being planarized on the polishing medium by engaging a contact element of a modulator with an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization to modulate the contour of a residual portion of the standing wave under a perimeter region of the substrate, and wherein the modulator comprises an active modulator having an actuator carrying the contact element and a controller coupled to the actuator, and wherein engaging the contact element with the exposed portion of the standing wave comprises selectively driving the actuator to move the contact element against the exposed portion of the standing wave in a manner that oscillates a pressure point of the residual portion of the standing wave under a perimeter region of the substrate to reduce a pressure concentration exerted by the pressure point against an area in the perimeter region of the polishing pad.
 53. In microelectronic device manufacturing, a method for controlling edge uniformity in planarization processes using a polishing medium, comprising modulating the contour of a planarizing surface on the polishing medium in a region spaced outwardly from a leading edge of a microelectronic substrate while the substrate is being planarized on the polishing medium by engaging a contact element of a modulator with an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization to modulate the contour of a residual portion of the standing wave under a perimeter region of the substrate, and wherein the modulator comprises an active modulator having an actuator carrying the contact element and a controller coupled to the actuator, and wherein engaging the contact element with the exposed portion of the standing wave comprises selectively driving the actuator to move the contact element against the exposed portion of the standing wave in a manner that attenuates a pressure point of the residual portion of the standing wave under a perimeter region of the substrate.
 54. In microelectronic device manufacturing, a method for controlling edge uniformity in planarization processes using a polishing medium, comprising modulating the contour of a planarizing surface on the polishing medium in a region spaced outwardly from a leading edge of a microelectronic substrate while the substrate is being planarized on the polishing medium by engaging a contact element of a modulator with an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization to modulate the contour of a residual portion of the standing wave under a perimeter region of the substrate, and wherein the modulator comprises an active modulator having an actuator carrying the contact element and a controller coupled to the actuator, and wherein engaging the contact element with the exposed portion of the standing wave comprises selectively driving the actuator to move the contact element against the exposed portion of the standing wave in a manner that attenuates and shifts a pressure point of the residual portion of the standing wave under a perimeter region of the substrate.
 55. In microelectronic device manufacturing, a method for controlling edge uniformity in planarization processes using a polishing medium, comprising selectively imparting a waveform to a region on a planarizing surface of the polishing medium proximate to a leading edge of a microelectronic substrate while the substrate is being planarized on the polishing medium, wherein imparting a waveform to the region of the planarizing surface comprises engaging a waveform surface of a modulator with an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization to modulate the contour of a residual portion of the standing wave under a perimeter region of the substrate.
 56. The method of claim 55 wherein the modulator comprises a passive modulator and the waveform surface has a desired shape defining a static waveform to attenuate the amplitude of the residual portion of the standing wave wider the perimeter region of the substrate, and wherein engaging the waveform surface with the exposed portion of the standing wave comprises pressing the waveform surface against the exposed portion of the standing wave at a desired downforce.
 57. The method of claim 55 wherein the modulator comprises a passive modulator and the waveform surface has a desired shape defining a static waveform to shift a pressure point of the residual portion of the standing wave under the perimeter region of the substrate, and wherein engaging the waveform surface with the exposed portion of the standing wave comprises pressing the waveform surface against the exposed portion of the standing wave at a desired downforce.
 58. The method of claim 55 wherein the modulator comprises an active modulator having an actuator carrying the waveform surface and a controller coupled to the actuator, and wherein engaging the waveform surface with the exposed portion of the standing wave comprises selectively driving the actuator to press the waveform surface against the exposed portion of the standing wave along a dynamic waveform that shifts a pressure point of the residual portion of the standing wave under a perimeter region of the substrate.
 59. The method of claim 55 wherein the modulator comprises an active modulator having an actuator carrying the waveform surface and a controller coupled to the actuator, and wherein engaging the waveform surface with the exposed portion of the standing wave comprises selectively driving the actuator to press the waveform surface against the exposed portion of the standing wave along a dynamic waveform that oscillates a pressure point of the residual portion of the standing wave under a perimeter region of the substrate to reduce a pressure concentration exerted by the pressure point against an area in the perimeter region of the substrate.
 60. The method of claim 55 wherein the modulator comprises an active modulator having an actuator carrying the waveform surface and a controller coupled to the actuator, and wherein engaging the waveform surface with the exposed portion of the standing wave comprises selectively driving the actuator to press the waveform surface against the exposed portion of the standing wave along a dynamic waveform that shifts and attenuates a pressure point of the residual portion of the standing wave under a perimeter region of the substrate.
 61. In microelectronic device manufacturing, a method of planarizing a microelectronic substrate, comprising: pressing a microelectronic substrate against a planarizing surface of a polishing medium; moving at least one of the substrate and the planarizing surface with respect to the other to move the substrate across the planarizing surface; and modulating the contour of the planarizing surface in a region spaced outwardly from a leading edge of the microelectronic substrate by engaging a contact element of a modulator with an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization to modulate the contour of a residual portion of the standing wave under a perimeter region of the substrate wherein the modulator comprises an active modulator having an actuator carrying the contact element and a controller coupled to the actuator, and wherein engaging the contact element with the exposed portion of the standing wave comprises selectively driving the actuator to move the contact element against the exposed portion of the standing wave in a manner that shifts a pressure point of the residual portion of the standing wave under a perimeter region of the substrate.
 62. In microelectronic device manufacturing, a method of planarizing a microelectronic substrate, comprising: pressing a microelectronic substrate against a planarizing surface of a polishing medium; moving at least one of the substrate and the planarizing surface with respect to the other to move the substrate across the planarizing surface; and modulating the contour of the planarizing surface in a region spaced outwardly from a leading edge of the microelectronic substrate by engaging a contact element of a modulator with an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization to modulate the contour of a residual portion of the standing wave under a perimeter region of the substrate, wherein the modulator comprises an active modulator having an actuator carrying the contact element and a controller coupled to the actuator, and wherein engaging the contact element with the exposed portion of the standing wave comprises selectively driving the actuator to move the contact element against the exposed portion of the standing wave in a manner that oscillates a pressure point of the residual portion of the standing wave under a perimeter region of the substrate to reduce a pressure concentration exerted by the pressure point against an area in the perimeter region of the polishing pad.
 63. In microelectronic device manufacturing, a method of planarizing a microelectronic substrate, comprising: pressing a microelectronic substrate against a planarizing surface of a polishing medium; moving at least one of the substrate and the planarizing surface with respect to the other to move the substrate across the planarizing surface; and modulating the contour of the planarizing surface in a region spaced outwardly from a leading edge of the microelectronic substrate by engaging a contact element of a modulator with an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization to modulate the contour of a residual portion of the standing wave under a perimeter region of the substrate, wherein the modulator comprises an active modulator having an actuator carrying the contact element and a controller coupled to the actuator, and wherein engaging the contact element with the exposed portion of the standing wave comprises selectively driving the actuator to move the contact element against the exposed portion of the standing wave in a manner that attenuates a pressure point of the residual portion of the standing wave under a perimeter region of the substrate.
 64. In microelectronic device manufacturing, a method of planarizing a microelectronic substrate, comprising: pressing a microelectronic substrate against a planarizing surface of a polishing medium, moving at least one of the substrate and the planarizing surface with respect to the other to move the substrate across the planarizing surface, and modulating the contour of the planarizing surface in a region spaced outwardly from a leading edge of the microelectronic substrate by engaging a contact element of a modulator with an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization to modulate the contour of a residual portion of the standing wave under a perimeter region of the substrate, wherein the modulator comprises an active modulator having an actuator carrying the contact element and a controller coupled to the actuator, and wherein engaging the contact element with the exposed portion of the standing wave comprises selectively driving the actuator to move the contact element against the exposed portion of the standing wave in a manner that attenuates and shifts a pressure point of the residual portion of the standing wave under a perimeter region of the substrate.
 65. In microelectronic device manufacturing, a method of planarizing a microelectronic substrate, comprising: pressing a microelectronic substrate against a planarizing surface of a polishing medium; moving at least one of the substrate and the planarizing surface with respect to the other to move the substrate across the planarizing surface; and selectively imparting a waveform to a region on the planarizing surface proximate to a leading edge of a microelectronic substrate by engaging a waveform surface of a modulator with an exposed portion of a standing wave on the planarizing surface formed at the leading edge of the substrate during planarization to modulate the contour of a residual portion of the standing wave under a perimeter region of the substrate, the imparted waveform altering a contour of the planarizing surface under a perimeter region of the substrate.
 66. The method of claim 65 wherein the modulator comprises a passive modulator and the waveform surface has a desired shape defining a static waveform to attenuate the amplitude of the residual portion of the standing wave under the perimeter region of the substrate, and wherein engaging the waveform surface with the exposed portion of the standing wave comprises pressing the waveform surface against the exposed portion of the standing wave at a desired downforce.
 67. The method of claim 65 wherein the modulator comprises a passive modulator and the waveform surface has a desired shape defining a static waveform to shift a pressure point of the residual portion of the standing wave under the perimeter region of the substrate, and wherein engaging the waveform surface with the exposed portion of the standing wave comprises pressing the waveform surface against the exposed portion of the standing wave at a desired downforce.
 68. The method of claim 65 wherein the modulator comprises an active modulator having an actuator carrying the waveform surface and a controller coupled to the actuator, and wherein engaging the waveform surface with the exposed portion of the standing wave comprises selectively driving the actuator to press the waveform surface against the exposed portion of the standing wave along a dynamic waveform that shifts a pressure point of the residual portion of the standing wave under a perimeter region of the substrate.
 69. The method of claim 65 wherein the modulator comprises an active modulator having an actuator carrying the waveform surface and a controller coupled to the actuator, and wherein engaging the waveform surface with the exposed portion of the standing wave comprises selectively driving the actuator to press the waveform surface against the exposed portion of the standing wave along a dynamic waveform that oscillates a pressure point of the residual portion of the standing wave under a perimeter region of the substrate to reduce a pressure concentration exerted by the pressure point against an area in the perimeter region of the substrate.
 70. The method of claim 65 wherein the modulator comprises an active modulator having an actuator carrying the waveform surface and a controller coupled to the actuator, and wherein engaging the waveform surface with the exposed portion of the standing wave comprises selectively driving the actuator to press the waveform surface against the exposed portion of the standing wave along a dynamic waveform that shifts and attenuates a pressure point of the residual portion of the standing wave under a perimeter region of the substrate. 